[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 270008 AAA
TWDAT

Tropical Weather Discussion...Updated
NWS National Hurricane Center Miami FL
0005 UTC Fri Oct 27 2023

Updated for Special Features

Tropical Weather Discussion for North America, Central America
Gulf of Mexico, Caribbean Sea, northern sections of South
America, and Atlantic Ocean to the African coast from the
Equator to 31N. The following information is based on satellite
imagery, weather observations, radar and meteorological analysis.

Based on 1800 UTC surface analysis and satellite imagery through
2100 UTC.

...SPECIAL FEATURES...

Storm Force Wind Warning Northwestern Atlantic (Post-Tropical
Cyclone Tammy): Post-Tropical Cyclone Tammy is centered
near 31.0N 59.5W at 26/1800 UTC. Estimated minimum central
pressure is 977 mb. Gale to strong gale winds, reaching hurricane
force closer to the center of the system N of the area, and seas
of 22 to 25 ft seas are noted from 29N to 31N between 57W and
63W. Scattered moderate and isolated strong convection is noted
from 28N to 31N between 58W and 66W. This system is forecast to
become separated from the front during the next day or so, and
environmental conditions are forecast to become more conducive
for the low to regain tropical characteristics while it meanders
over the northwestern Atlantic to the east of Bermuda through
Saturday. Regardless of tropical redevelopment, the system is
likely to bring gusty winds and heavy rainfall to Bermuda during
the next couple of days. Interests on Bermuda should monitor the
progress of this system. This system has a medium chance of
tropical cyclone formation through the next 48 hours. Please
read the latest NHC Tropical Weather Outlook at
www.hurricanes.gov and the latest HIGH SEAS FORECAST at
www.hurricanes.gov/marine for more details.

Western Atlantic Rough Seas: Swell generated from Tammy combined
with swell generated from strong gradient flow that developed
west of Tammy is supporting a large area of 12 ft seas over the
western Atlantic waters N of 24N between 55W and 70W. Mariners
should either avoid this region or use extreme caution in this
area, depending on your vessel type and cargo. Hazardous surf and
rip currents are also anticipated along the coast of central
Florida, the Bahamas, Greater Antilles and the northern Leeward
Islands. The seas of 12 ft or greater will generally continue over
the waters N of 23N between 55W and 71W before subsiding early
this weekend. Please read the latest HIGH SEAS FORECAST issued
by the National Hurricane Center at the website
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml and the Offshore
Waters Forecast at https://www.nhc.noaa.gov/marine/offshores.php
for more details.

...MONSOON TROUGH/ITCZ...

A monsoon trough enters the Atlantic off the coast of Africa near
12.5N16.5W to 08.5N20W. It then transitions to ITCZ and extends to
near 09N37W. Scattered moderate convection is noted from 06N to
14N between 20W and 35W.

...GULF OF MEXICO...

A ridge of high pressure extends across the Gulf coast states.
Fresh to strong winds prevail over the Florida Straits with
moderate winds noted elsewhere over the Gulf waters. Seas are in
the 7-8 ft range over the Gulf of California and 5-7 ft elsewhere.

For the forecast, high pressure centered north of the area will
continue to support moderate to fresh winds, locally strong in the
eastern Gulf, through the remainder of the week. Mainly gentle NE
winds are expected this weekend as the pressure gradient weakens
and high pressure settles over the region. The next cold front is
forecast to reach the NW Gulf on Mon. This front could bring gale
force winds and building seas over the western Gulf early next
week.

...CARIBBEAN SEA...

An upper level trough extends across the waters from Hispaniola
to the SW Caribbean. This trough is helping to support active
convection over much of the Caribbean waters S of 18N. Fresh to
strong winds, and seas of 5-7 ft, are noted over the waters N of
15N and W of 70W. Light to gentle winds, and seas of 3-5 ft are
noted elsewhere.

For the forecast, strong high pressure N of the area will
continue to support fresh to occasionally strong NE to E winds in
the NW and north- central Caribbean, including the Windward
Passage through the week. Gentle winds are expected elsewhere.

...ATLANTIC OCEAN...

Please read the Special Features section above for more on a Storm
Warning associated with Post-Tropical Cyclone Tammy southeast of
Bermuda, and rough seas across the western Atlantic.

A cold front extends from 31N53W to 23N57W. Scattered moderate and
isolated strong convection is noted within 90 nm east of the
front. A surface trough is found from 17N46W to 10N47W. Scattered
moderate convection is noted within 120 nm east of the trough
axis.

Fresh to strong winds are noted west of 65W, with fresh to near
gale winds elsewhere south of Tammy N of 26N between 55W and 65W.
Gentle to moderate winds are noted elsewhere. Aside from the area
of 12 ft seas, seas of 8-11 ft are noted N of 19N and W of 50W.
Seas of 5-7 ft are elsewhere over the discussion waters.

For the forecast W of 55W, strong extratropical cyclone (former
Tammy) associated with an occluded front is located near 31N59W or
a few hundred miles east-southeast of Bermuda. There is a
possibility that this system could regain tropical or subtropical
characteristics while it meanders over the northwestern Atlantic
through early next week. High winds and hazardous seas are still
present, and a Storm Warning remains in effect for portions of the
area SE of Bermuda. Gales will continue into Fri. The gradient
between former Tammy and high pressure N of the area will continue
to support strong to near gale-fore NE winds and very rough seas
well W of former Tammy across much of the forecast area through
the week.

$$
AL/jrl
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